2. Cell Membrane Diagram
Draw a diagram of the cell membrane. Please include (and label):
Phospholipid bilayer (hydrophilic and hydrophobic)
Protein channel
An ion pump
Cholesterol
Gylcoproteins*
Define the function of each as it relates to the function of the membrane and cell
(You will have some time on block day to work on this as well)
For the function of glycoproteins and glycolipids, maybe give one specific example?

3. Block day Grade quizzes Organelle partner quiz
Finish cell membrane diagram
Membrane transport notes *
Transport and application in body

4. Cell Structure and Function
Human cells share the common features of:
Plasma membrane
Cytoplasm
Nucleus structure
Which all operate together to provide cellular functions.

5. The Plasma Membrane
Separates the extracellular and intracellular compartments of the body
Regulates the movement of materials between these compartments
How does the plasma membrane relate to homeostasis?

6. Membrane Structure
Equal amounts--by weight-- lipid and protein molecules, with a small amount of carbohydrates
The lipid component
Phospholipids
Two parts
HEAD=hydrophilic TAIL=hydrophobic
Usually liquid and fluid
Cholesterol
Provide the stabilizing influence and increase the strength of the membrane

7. Membrane Structure
Equal amounts--by weight-- lipid and protein molecules, with a small amount of carbohydrates
The protein component
Peripheral
Attached to the outside and inside SURFACES
Integral
More numerous
Have at least some portion WITHIN the membrane
Most extend all the way through
These would be channels for transport

8. Membrane Structure
Equal amounts--by weight-- lipid and protein molecules, with a small amount of carbohydrates
The carbohydrate component
May be attached to the protein component and help in communication
The two together would be GLYCOPROTEINS
Serve as receptors to distinguish between the different cell types
Think LABELS
Hormones, growth factors, antibodies, etc.

9. Membrane Function Passive processes Active processes
Why is it necessary to regulate what enters and leaves a cell?
The membrane is SELECTIVELY PERMEABLE
Only some things can enter or leave
Various transport mechanisms, grouped by the amount of energy needed
Passive processes
Active processes
Which one uses energy? Which one does not use energy? What kind of energy?

10. Membrane Function Passive Processes Diffusion
Molecules move from an area of HIGH concentration to LOW concentration
Try drawing a diagram of this in a way that makes sense to you
Movement will continue until EQUILIBRIUM
A difference in one concentration (amount) from one area to another is called a concentration gradient
Examples?
Facilitated diffusion
Same idea as diffusion but the molecules that are trying to move are too large to cross the membrane and need assistance
Which molecules can help with this process?

11. Membrane Function Passive Processes
3. Osmosis: the movement of WATER molecules only, across the membrane
Still from an area of high concentration to low concentration--BUT OF WATER!
Water concentration = the amount of solutes present
Many solutes = low water concentration
Vice versa
ISOTONIC SOLUTION: concentration of solutes is the same on both sides (of the barrier, membrane, etc.)
HYPERTONIC SOLUTION: the solution on the outside has MORE solutes (high concen.) than whatever is in the solution
HYPOTONIC SOLUTION: the solution on the outside has LESS solutes (low concen.) than whatever is in the solution
EXAMPLE: a cell in a beaker of salt water...

12. Membrane Function Passive Processes
4. Filtration: movement of molecules from an area of high PRESSURE to low PRESSURE
In the cell, small molecules are physically pushed through the plasma membrane by a pressure gradient
EXAMPLE: in the kidneys, where blood pressure forces small molecules such as water, small ions and waste (urea) between the plasma membranes of the thin cells of the blood vessels and kidney tubules

13. Membrane Function Active Processes Use energy supplied by the cell
In the form of….ATP!
Usually against the concentration gradient (from LOW concen. To HIGH concen.)
Think… UPHILL
Active Transport: requires ATP and integral proteins, called carriers
Ex: Sodium-potassium pump in neurons
Neurons need a concentration gradient in order
to function

14. Membrane Function
Active Processes

15. Membrane Function Active Processes
2. Cytosis: the transport of large volumes of materials and large particles across the plasma membrane
Two types
Endocytosis: INTO the cell (Think...ENTER)
Exocytosis: OUT of the cell (Think...EXIT)
This happens by extending part of the membrane around the material and enclosing it